29 terms

FTCE Chemistry

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Intensive property
Intensive properties of a substance are not dependent on the size or mass of the sample and cannot be determined by simply looking at the substance.
What are examples of intensive properties?
BP, MP, density, temp, and pressure
Extensive properties
Extensive properties of a substance are dependent on the amount of matter present in each sample.
What are examples of extensive properties?
mass and volume
Heat
which has units of energy, is the transfer or exchange of thermal energy caused by a temperature difference
Temperature
is a measure of the thermal energy of matter (not the exchange of thermal energy).
On the Fahrenheit (°F) scale,
water freezes at _______°F; and
water boils at ________°F.
Room temperature is approximately ________ °F
32, 212, 72
On the Celsius (°C) scale,
water freezes at ________ °C; and
water boils at _________°C.
Room temperature is approximately __________ °C.
0, 100, 22
The _______________________scale avoids negative temperatures by assigning 0 K to the coldest temperature possible, absolute zero.
Absolute zero is the temperature at which molecular motion virtually stops
Kelvin (K)
On the Kelvin (K) scale,
water freezes at ___________ K; and
water boils at ___________ K.
Room temperature is approximately ____________ K.
273,373,295
Heat capacity
The quantity of heat (usually in joules) required to change the temperature of a given amount of the substance by 1 °C (also in kelvins).
When the amount of the substance is expressed in grams, the heat capacity is called the __________ ___________ ______________ (or the specific heat) and has units of joules per gram per degree Celsius, J/g °C (also in kelvins).
specific heat capacity
In a ____________ _____________, the appearance of matter may change, but its composition does not.
physical change
In a _____________ _____________, the composition of matter changes.
chemical change
An _____________ is the smallest identifiable unit of an element
atom
An __________ is a substance that cannot be broken down into simpler substances.
element
Dalton's atomic theory has three parts:
1. Each element is composed of tiny, indestructible particles called atoms.

2. All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements.

3. Atoms combine in simple, whole-number ratios to form compounds.
An English physicist named J. J. Thomson (1856-1940) discovered a smaller and more fundamental particle called the __________________.
electron
Rutherford's gold foil experiment (1909):
1. Most of the atom's mass and all of its positive charge are contained in a small core called the nucleus.
2. Most of the volume of the atom is empty space through which the tiny, negatively charged electrons are dispersed.
3. The number of negatively charged electrons outside the nucleus is equal to the number of positively charged particles (protons) inside the nucleus, so that the atom is electrically neutral.
The law of constant composition states ( Joseph Proust (1754-1826) )-
All samples of a given compound have the same proportions of their constituent elements.
A _________________indicates the elements present in a compound and the relative number of atoms of each.
chemical formula
How to List the Elements in Order in Compounds :
-Chemical formulas list the most metallic elements first
-In compounds that do not include a metal, the more metal-like element is listed first.
-Within a single column in the periodic table, elements toward the bottom are more metal-like than elements toward the top.
An ______________ ______________ gives the relative number of atoms of each element in a compound.
empirical formula
A ______________ _________________ gives the actual number of atoms of each element in a molecule of the compound.
molecular formula
A ____________ ___________________ uses lines to represent chemical bonds and shows how the atoms in a molecule are connected to each other.
structural formula
Molecular compounds
are compounds formed from two or more nonmetals. The basic units of molecular compounds are molecules composed of the constituent atoms.
Ionic compounds
contain one or more cations paired with one or more anions.
Pure substance
Polyatomic Ions